The effects of electrically exploding gold bridgewires into inert and explosive powder beds

Journal Article · Sat Oct 23 00:00:00 EDT 2021 · Shock Waves

DOI:https://doi.org/10.1007/s00193-021-01041-7· OSTI ID:1827248

Rae, P. J. ; Rettinger, R. C.

Abstract The particle velocity created in beds of both low-density inert sugar and explosive PETN as a function of distance from an exploding bridgewire was measured using optical velocimetry and a silvered PMMA window. As expected, more violent bridge-bursts (from a greater-stored-energy capacitive discharge unit) resulted in greater particle velocities and a better supported compaction wave in sugar. In all cases, ramp waves, not shocks, were observed in the inert sugar. Large window velocities were observed for very powerful bursts (up to 270 m/s), but bursts required for stochastic detonator operation conditions resulted in sugar/PMMA window velocities of only 8–10 m/s 0.85 mm from the bridge location. In contrast, after a distance of only 0.65 mm, a building shock wave was observed in PETN under both threshold and reliable firing conditions. Subsequently a hot-spot-driven shock-to-detonation (SDT) process was observed prior to full detonation. The measured buildup process accounts for $$$$\approx $$$$ $\approx$  66% of the so-called excess transit time (ETT) between the observed and theoretical total function time for the particular exploding-bridge-wire (EBW) detonator studied. The remainder must occur in the powerful output pellet region. In contrast to a common understanding, the ETT is found to be a weak function of the discharge energy. Thus, the operation of the detonator after a bridge-burst energy-to-powder reaction transition process is found to be hot-spot-driven SDT in both the low- and high-density pellets.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE Laboratory Directed Research and Development (LDRD) Program
• Grant/Contract Number: 20210189ER; 89233218CNA000001
• OSTI ID: 1827248
• Alternate ID(s): OSTI ID: 1855135
• Report Number(s): LA-UR-21-23993; PII: 1041
• Journal Information: Shock Waves, Journal Name: Shock Waves Vol. 31 Journal Issue: 8; ISSN 0938-1287
• Publisher: Springer Science + Business Media
• Country of Publication: Germany
• Language: English

Related Subjects

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
explosive
detonators
bridgewire
shock compaction
PETN
powder